Sound-box.



T; H. MACDONALD.

SOUND BOX.

APPLICATION FILED JULY 21, 1910.

Patented Mar. 24, 191$ wmwo; M144 I 314-00, wlfoz freedom.

ll idillll ll ll .lifdllj GJRAPHOPHQNTE comenmr, WEST vmenmn 0B IBELIDGEJPQRT, CONNECTICUT, A CORPOBJATION OF peeificellon of Letters la'i'enlsl ipplicetlon med July 21;, me.

Patented Men. 24, 1914, Serial No. $73,061.

To aZl whom it may concern:

Be it known that l, 'lnomne ll. Mne- DONALD; e citizen of the United Stulee'of America, and u resident of BKlClgGPOFlJ, Connecticut, have invented e new and useful Sound-Box, which. invention is fully eel: forth in the following specification.

My invention relelee to sound-boxes for tz'alkinguinuchines pertieului'ly those of the type operating upon zigzag sound-rem ords. v

The objects of inveulion are to oheepen and simplify the consur'uclion of the sound-hex, and to improve the quality of its audible ieproduotion.

The invention comprises the pivoting ol. the styluslevei' upon p0 e axis, consisting preferably cor ugge, end the locating of the stylus and 1 mid air-lie in the plune'of the diaphragm,

, The invention further C(Il cure yet readily detachable n diaphragm in such munr confined against vihiuting rises the se- -/.i the utmost find, finally e invention consists in lhe various oh of construction and arrrmgeincnt hereinniltiei' pointed out and claimed.

The invention will be best understood by reference to the annexed di'ziwing's that illneti'ule u preferred embodiment izhe'reoi.

Figure l is a firont view 01 elevation of my improved aound-hox; Fig. if; an edge view thereof, partly in section; and Fig. 3 is a detail, on an enlarged scale, showing the manner of secliu'ingz; "the diaphragm in place.

The head or casing 1. consists of a shallow circular cup liming the i'uai'ginal rim 2, the hollow neck 3 that surrounds the central uperure in i'he head and lhe two parallel lugs 4ll that project from the rim 2 Pre fomhly these parts are an integral casting, which may he of aluminum or other suitable material; and preferably the outer side oi? the heck may be hollowed out as indicated in Fig. 3, 01- the sake of lightness. inside the concavity of the head end around the periphery of its flow is an annular groove, semi-circular in 01:09; Lion; in which is placed a yielding: gash. preferably a smell IlllllKl tubing 5. Upon ihis is llll l the dia- "phcugm C, prefeireloly of -nhln iinuui, and preferably having concentric corrugations ing' device is shown es a. split ring 9, and on either side of the split in said ring is a hole or semi: 10. inserting the tips oi n pair of pliers inlto these "holes 10-l0 and compreseing the pliers, the split hing may be closed; it then placed upon the upper gasket ready enter the recess lest-mentinned and lay removing the pliers ihe icing 9 expands inifio groove and engages beneath lip 8, thus locking the diaphragm 3ecurely but yieldinn'ly in place. To remove the diephmgrn, the holes ill-16 are forced togethei." by the pliers, when lshe ring 9 in removed and the diaphragm taken out.

The stylus-level. 11 lies parallel $0 the diaphragm and extends radially thereof its in z'ivet 12 in the well known menner; While lts outer end 15 similarly turned down to con met with its pivot-block 13, which is located v between the lugs 4i- The pivot-block is preferably made integral with lever 11, and carries the reproducing-stylus or needle 14, which latter extends in the prolongation of e radius of the diephregmfi, and referably lies in substantially the plane o'fthe diaphrngm. Pivot-block 13 is poeitivel pivoted transversely of the prolonged m ius last referred to.' The preferred pivoting comprises cone-tipped screws l515, screwthreed'ed through lugs 4%, to enter corresponding cone-seats in the adjacent feces of pivot-block 13. The axes of these two screws are of course in the same line, and preferably they lie in suhslzmitially the same plane the diaphragm], extending el; right angles to the prolonged lll'illllS lash referred to. So that the 'posilzive pivot or miis of the pivot? block", the iliphrngm itself, and the stylus 14, all lie in substantially the same plane. By reaeonol this construction and arrangement the vibrations of the needle are transinitted directly and truly, and in most sensitive fashion, to the diaphragm. The needle is shown as inserted into a socket in the end of pivot-block 13, where it is held by, a setscrew 16; but any other mounting for the needle maybe employed. Care should be taken iii-properly and accurately centering the cone-bearings; and preferably one or more jam nuts 17 will be employed at the outer ends of screws 15, to hold the latter against turning, to insure a permanent adjustmentu Preferably a rin or washer 18, of yielding material, as so t rubber, encircles neck 3 and rests against the back of the sound-box, being covered by a flanged plate 19, which may be cemented thereto, the down-turned flange not contacti v with head 1. The neck 3 is shown as provi ed with a bayonet-joint groove 20, for securing it to the-tone-arm or other sound-conveyer. The function of the yielding block 18 is to prevent rattle of the sound-box: against the arm, but flange-plate 19 and even the yielding washer 18 may be omitted if desire The strikin features of my novel soundbox are its'lig tness and simplicity, the few ness of its parts, the ease of'manufacturing and assembling the parts, readiness of dis assemblage for repairs, etc, and the brilliant excellence of the audible reproductions obtained by itsuse.

I have,described my invention with some particularity of detail, but only for the sake of clearness, since parts may be used to the exclusion of other'parts, and modifications may" be resorted to in the construction or in the arrangement of the various arts, without-departing from the spirit 0 my invention, which broadly stated consists in locating the stylus or needle and the positive axis of its lever in substantially the same plane with the diaphragm, and in securely yet detachably mounting the diaphragm yieldingly within the head of the sound-box.

Having thus described my invention, I claim:

A sound-box comprising an integral on with a central opening and having aroun the periphery of the floor of its concavity an annular groove'and near the top of the cup an annular recess, two lugs projecting outwardly from the walls of said cup, two yielding gaskets in said concavity, one of which is located in said groove, a diaphragm interposed between said gaskets, a split ring having an outwardly projecting peripheral flange, which ring rests upon said second gasket with its flange in said recess to hold said gaskets and said diaphragm in place, said flange being of less thickness than the width of said recess to provide a clearance to permit of the ready removal of said ring a reproducing needle lying in the plane oi said diaphragm and extending radially therefrom, a stylus-lever connecting said diaphragm and said needle, said lever being provided with a pivot lying in the plane of the needle and the diaphragm and having bearing in said lugs, substantially as described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

THOMAS H. MACDONALD.

lVitnesses 2 GLENnonA FLINT, J HN S. GRIFFITH. 

